Abstract A circuit board made according to the method of insulating the terminal holes passing through a printed-circuit board having a metallic core wherein the surfaces of the circuit board carrying the printed-circuits are first overlaid with a protective layer of polyester material. Holes are drilled or punched through the printed-circuit board as dictated by the circuit requirements, and the holes are filled with a flowable insulating material. Air is caused to flow through the holes thereby removing excess insulating material therefrom, and leaving a portion of the insulating material adhered to the walls of the holes. The insulating material is dried and cured to form a hardened lining of insulating material in the holes. The circuit board is the product resulting from practice of the aforesaid method.
A CIRCUIT BOARD INCLUDING A SUPPORTING SUBSTRATE OF RIGID METAL, A CONDUCTIVE CIRCUIT, MEANS SECURING SAID CIRCUIT TO SAID SUBSTRATE AND INSULATING SAID CIRCUIT THEREFROM, SAID SUBSTRATE AND CIRCUIT HAVING A TERMINAL HOLE THERETHROUGH, AND A LINING OF INSULATING MATERIAL HAVING A SUBSTANTIALLY UNIFORM CROSSSECTION AND BEING ADHERED TO THE WALL OF SAID HOLE, SAID MATERIAL EXTENDING BETWEEN THE DISTAL EXTREMITIES OF SAID HOLE, SAID INSULATING MATERIAL INCLUDING COLLOIDAL SIZED PARTICLES OF CERAMIC HOMOGENOUSLY SUSPENDED IN A HARDENED BINDER.
Claim 2
Dependent Claim
79 words
A CIRCUIT BOARD INCLUDING A SUPPORTING SUBSTRATE OF RIGID METAL, A CONDUCTIVE CIRCUIT, MEANS SECURING SAID CIRCUIT TO SAID SUBSTRATE AND INSULATING SAID CIRCUIT THEREFROM, SAID SUBSTRATE AND CIRCUIT HAVING A TERMINAL HOLE THERETHROUGH, AND A LINING OF INSULATING MATERIAL HAVING A SUBSTANTIALLY UNIFORM CROSSSECTION AND BEING ADHERED TO THE WALL OF SAID HOLE, SAID MATERIAL EXTENDING BETWEEN THE DISTAL EXTREMITIES OF SAID HOLE, SAID INSULATING MATERIAL INCLUDING COLLOIDAL SIZED PARTICLES OF CERAMIC HOMOGENOUSLY SUSPENDED IN A HARDENED BINDER.
Claim 3
Dependent Claim
19 words
The circuit board of claim 1 including a hermetic sealing material adhered to the exposed surfaces of said lining.
Claim 4
Dependent Claim
14 words
The circuit of claim 2 in which said sealing material includes a silicone monomer.
Claim 5
Dependent Claim
14 words
The circuit board of claim 2 wherein said binder is a hardened epoxy resin.
Claim 6
Dependent Claim
15 words
The circuit board of claim 4 wherein said sealing material is a polymerized silicone monomer.
Claim 7
Dependent Claim
18 words
The circuit board of claim 1 including a layer of conductive material on the surface of said lining.